Apparatus for making tires

ABSTRACT

An apparatus for making tires which include a separable mold which has an inner surface which defines the outer shape of a tire to be formed. A generally flat paddle shaped template member extends generally radially within the mold when it is assembled and the cross sectional shape of the tire is determined by the space between the template and the inner surface of the mold. The mold is rotated about its axis while the template member is preferably held in a fixed position. A flowable and hardenable elastomeric material suitable for use in constructing tires (such as polyurethane) is introduced into the rotating mold and centrifugal force urges the flowable material to the inner surface of the mold and when sufficient elastomeric material has been added, the wiping action of the template member on the elastomeric material forms the inner shape of the tire. The material hardens and the mold, the template member and finished tire are separated. The template member is preferably held in a fixed position, however, it may be rotated at a slower speed than the mold or in a reverse direction.

United States Patent lleneze 1 1 APPARATUS FOR MAKING TIRES [72]Inventor: Heinz Wilhelm Beneze, Akron, Ohio [73] Assignee: The FirestoneTire & Rubber Company, Akron, Ohio [22] Filed: April 27, 1970 [21] Appl.No.: 43,281

Related US. Application Data [62] Division of Ser. No. 796,466, Feb. 4,1969, Pat.

[52] US. Cl. ..425/426, 264/311, 425/35, 425/242 [51] Int. Cl. ..B29c5/00, B29h 3/08 [58] Field of Search ..264/3l1; 25/30 C, 30 R; 18/26 RR,42 D, 42 T, 42 M [56] References Cited UNITED STATES PATENTS FOREIGNPATENTS OR APPLICATIONS France ...l8/ 42 T 1 1 Oct.3, 1972 445,7904/1936 Great Britain ..25/ 30 RR Primary Examiner-J. Howard Flint, Jr.

Attorney-S. M. Clark and Gordon B. Seward [57] ABSTRACT An apparatus formaking tires which include a separable mold which has an inner surfacewhich defines the outer shape of a tire to be formed. A generally flatpaddle shaped template member extends generally radially within the moldwhen it is assembled and the cross sectional shape of the tire isdetermined by the space between the template and the inner surface ofthe mold. The mold is rotated about its axis while the template memberis preferably held in a fixed position. A flowable and hardenableelastomeric material suitable for use in constructing tires (such aspolyurethane) is introduced into the rotating mold and centrifugal forceurges the flowable material to the inner surface 1 of the mold and whensufficient elastomeric material has been added, the wiping action of thetemplate member on the elastomeric material forms the inner shape of thetire. The material hardens and the mold, the template member andfinished tire are separated. The template member is preferably held in afixed position, however, it may be rotated at a slower speed than themold or in a reverse direction.

10 Claims, 3 Drawing, Figures PATEN 0013 922 SHEEI 1 OF 2 PATENTEIJUBT 31972 SHEET 2 BF 2 QUE core as well as the difficulty in removing thecore from the formed tire. The present invention lends itself to otherrigid member by suitable fasteners 45. The pedestal support 44 includesa sleeve bearing, not numbered, which serves to mount a shaft 46. Apaddleshaped template member 48 is provided which has first and secondend portions 49 and 50, respectively. In the assembled condition of theapparatus, the template member 48 assumes the position of FIGS. 1 and 2and as will be noted, the template member is connected to the left endof shaft 46. The connection is best seen in solving these disadvantagesin that the large core is replaced by one or more small, preferablyflat, template members which are positioned within the mold and extendin a generally radial direction with respect thereto. The space betweenthe template members and the mold controls the shape of the tire whichis formed. The template members are easy to handle and easy to removefrom the finished tire.

An object of the present invention is to provide an improved apparatusfor producing synthetic tires, particularly of polyurethane.

Another object. of the present invention is to provide an apparatus formaking tires, particularly of the pneumatic type, which utilize arotating mold and a relatively stationary template member wherebyflowable and hardenable elastomeric material is thrown against the innersurface of the mold by centrifugal force to form the outer shape of thetire and as the volume of elastomeric material is increased the innershape of the tire is determined by the wiping action of the templatemember against the elastomeric material.

Other objects and a fuller understanding of this invention may be had byreferring to the following description and claims, taken in conjunctionwith the accompanying drawings, in which:

FIG. 1 is an elevational view partially in section of the apparatus ofthe present invention;

FIG. 2 is a view taken generally along the line 2-2 of FIG. 1; and

FIG. 3 is a view similar to FIG. 1 but showing the apparatus in theprocess of being disassembled.

Referring to the drawings, the apparatus of the present invention hasbeen indicated generally by the reference numeral 20 and as will beseen, includes a base 23 which serves to mount a pedestal support 25.The pedestal support 25 mounts a sleeve bearing which has beenunidentified, and this sleeve bearing serves to rotatably support ashaft 27. The right end of the shaft 27 as seen in FIG. 1 serves torotatably support a mold assembly identified generally by the referencenumeral 29. The mold assembly 29 includes a first side member 31 whichis fixed to the shaft 27 by means of a bolt 30 and a second side member32 is located in axially spaced relation to the side member 31. Thesetwo side members 31 and 32 are held in position in the assembledcondition by means of a ring member 34 and connecting bolts 35 whichextend through both'side members and the ring member.

An electric motor 37 is supported on the pedestal 25 and serves torotatively drive the shaft 27 by means of a pulley 38 which extendsbetween sheave members 40 and 41, respectively connected to the motorshaft and the shaft 27.

A second pedestal support 44 is located on the other side of the moldassembly from pedestal support 25 and this pedestal support is fixedlysecured to a floor or FIG. 2 and it will be seen that the end portion 49is cylindrical in configuration and resides between portions 66 and 77which are integrally connected to shaft 46. A set screw 68 extendsthrough portion 66 and into an annular groove 69 on 49. When screw 68 istightened the position of template member 48 is fixed and when loosenedit may be rotated about its length axis and it may pivot with respect toshaft 46 about the axis of set screw 68. An attachment housing 70 iswelded to the sleeve hearing which supports shaft 46 and has first andsecond flanges 71 and 72 which are located on either side of side member32 as best seen in FIG. 1. A bolt 73 extends through flange 71 and intomember 32 and a bolt 84 extends through flange 72 and into member 70when the mold is to be separated (See FIG. 3), however, when the mold isto be rotated in its assembled condition the bolt 73 is removed. Whenrotated the side member 32 moves between the fixed flanges 71 and 72.

A motor 54 is supported by the pedestal 44 and is adapted to rotativelydrive (in either direction) the shaft 46 when desired by a drive trainconsisting of a pulley 55 connected to sheaves 56 and 57. In mostinstances, the shaft 46 is not rotated, but rather is held in a fixedposition and this can be accomplished by means of an operator dropping apin 58 into aligned openings in the shaft 46 and in the pedestal support44.

In order to produce a pneumatic tire with the apparatus of the presentinvention, the mold assembly 29 is rotatively driven by the motor 3 7and while being so rotated the template member48 is held in a fixedposition relative thereto. A flowable and hardenable elastomericmaterial is introduced into the interior of the mold assembly through aconduit 74 which extends into the housing 70 and centrifugal forceserves to throw this flowable elastomeric material outwardly against thering member 34. As more material is added, the space which is providedbetween the second end portion 50 of the template member and the moldassembly begins to fill up until the cross section of the tire 67 whichis shown in FIG. 1 is completely formed. It will be seen that the outerconfiguration of the tire is formed by the inner surface of the ringmember 34 and side members 31 and 32. The inner surface of the pneumatictire is formed by the shape of the end portion 50 of the template member48 and the wiping action thereof on the elastomeric material. As theflowable elastomeric material is continually rotated, it begins toharden and finally hardens or cures to a point that the shape of thetire is self-supporting and the template member may be removed.

When this point has been reached, the set screw 68 is loosened by awrench and access is provided through an opening (in housing 70) whichhas not been shown. The template member is then rotated about its lengthaxis to the position shown in FIG. 3. The pedestal support 25 whichrests upon the base 23 is movable relative thereto. This is accomplishedby means of a rack gear 60 being fixedly secured to the base 23 and apinion gear 61 meshing therewith and rotatively'supported by thepedestal support 25. The pinion gear 61 is rotatively driven by way of ashaft 64 in'turn driven from a power source not shown and a chain 63interconnected with the pinion gear. It will therefore be. clear'that inorder to remove the template member after the tire has hardenedsufficiently to support itself, it is necessary to disconnect theconnecting bolts'35 and move the pedestal support 25 to the left asshown in FIG. 3 by rotatively driving the pinion gear 61. It will beseen that the second end portion 50 of the template member 48 separatesfrom the finished tire by simply pivoting about the screw 68 and comingoutthe opening in the tire. Before the tire is removed from the mold itisusually cured further either with or without heat. In order todemonstrate the use of the present apparatus in the method of producinga pneumatic tire, a flowable and hardenable elastomeric materialpolyurethane was utilized. The mold assembly 29 was driven atapproximately 700 rpm and the polyurethane which had the followingcharacteristics, was added to the mold assembly over a period ofapproximately 3 minutes. The polyurethane utilized comprised 100 partsof a pre polymer (Adiprene ll67 having a Brookfield viscosity of5,0007,000 centipoises at 86 F and 250-350 centipoises at 212 F andmixed with 20 parts of dioetylphthlate and 20 parts of MOCA 4,4methylene-bis(2 chloroaniline). The overall viscosity entering the moldwas 200-1 ,000 centipoises. After an additional period of time, thepneumatic tire had been sufficiently formed and was hardened to acondition where it would support the formed shape. It will be apparentto those skilled in the art that satisfactory flowable and hardenablematerials other than polyurethane might be utilized (such as vinylplastisols and nylon) in a manner which would not depart from theteachings of the present invention.

ltis preferred that the template member 48 be held in a fixed position,however, it will be clear that the template member may be rotated bymeans of the motor 54 and the drive train, at a slower speed than themold assembly 29 or it may be rotated in the opposite direction. I

From a review of the above, it will be readily apparent to those skilledin the art that a new and highly advantageous apparatus for makingpneumatic tires has been disclosed and that the objects of thisinvention as hereinabove enumerated are readily carried out.

Although this invention has been described in its preferred-form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred form has been made only by way of exampleand that numerous changes in the details of construction and thecombination and arrangement of parts may be resorted to withoutdeparting from the spirit and scope of the invention as hereinafterclaimed.

What is claimed is:

1. Apparatus for molding tires including in combination a mold having aninner surface and comprising first and second axially spaced sidemembers connected at their outer peripheries by a ring member, meansmounting said mold for rotation about its axis with said axis beingdisposed generally in a horizontal plane, means for rotating said moldabout its horizontal axis wall means defining an opening to the interiorof said mold for introducing flowable and hardenable material suitablefor use in constructing tires thereinto, at least one template memberpositioned within said mold and extendingtherein in a generally radialdirection, said template member comprising a plate member having anouter perimetric surface which conforms to the inner cross sectionalshape of the tire to be molded and having a relatively small thicknessdimension in the circumferential direction of the mold, theshape of thetire being determined by the space between the perimetric surface ofsaid template member and said inner surface of said mold. v

2. Apparatus for molding tires as claimed in claim 1, wherein means areprovided for fixedly locating said template member within said moldduring rotation of the mold. I

3. Apparatus for molding tires as claimed in claim 1, wherein means areprovided for rotating said template relative to said mold. t

4. Apparatus for molding tires as claimed in claim 1, wherein means areprovided for supporting said template member which permits said templatemember to be rotated about its generally radical direction length Y axiswhen desired.

5. Apparatus for molding tires including in combination a mold having aninner surface which defines the outer shape of a tire, means mountingsaid mold for rotation about its axis, means for rotating said moldabout its axis, wall means defining an opening to the interior of saidmold for introducing flowable and hardenable elastomeric materialthereinto, at least one template member positioned within said mold andextending therein in a generally radial direction, said template membercomprising a plate member having an outer perimetric surface whichconforms to the inner cross sectional shape of the tire to be molded andhaving a relatively small thickness dimension in the circumferentialdirection of the mold, the shape of the tire being determined by thespace between said perimetric surface of said template member and saidinner surface of said mold.

6. Apparatus for molding tires as claimed in claim 5, wherein means areprovided for fixedly locating said template member within said moldduring rotation of the same.

7. Apparatus for molding tires as claimed in claim 5, wherein means areprovided for rotating said template member relative to said mold.

8. Apparatus for molding tires as claimed in claim 5, wherein means areprovided for supporting said template member which permits said templatemember to be rotated about its generally radial direction length axiswhen desired.

9. Apparatus for molding tires as claimed in claim 5, wherein said moldhas a circumferentially extending opening thereinto having a widthdimension in the axial direction of said mold, the thickness dimensionof said plate member being less than said width dimension of saidcircumferentially extending opening. 5

10. Apparatus for molding tires as claimed in claim 1, wherein said moldhas a circumferentially extending opening thereinto having a widthdimension in the axial direction of said mold, the thickness dimensionof said plate member being less than said width dimension of saidcircumferentially extending opening.

1. Apparatus for molding tires including in combination a mold having aninner surface and comprising first And second axially spaced sidemembers connected at their outer peripheries by a ring member, meansmounting said mold for rotation about its axis with said axis beingdisposed generally in a horizontal plane, means for rotating said moldabout its horizontal axis wall means defining an opening to the interiorof said mold for introducing flowable and hardenable material suitablefor use in constructing tires thereinto, at least one template memberpositioned within said mold and extending therein in a generally radialdirection, said template member comprising a plate member having anouter perimetric surface which conforms to the inner cross sectionalshape of the tire to be molded and having a relatively small thicknessdimension in the circumferential direction of the mold, the shape of thetire being determined by the space between the perimetric surface ofsaid template member and said inner surface of said mold.
 2. Apparatusfor molding tires as claimed in claim 1, wherein means are provided forfixedly locating said template member within said mold during rotationof the mold.
 3. Apparatus for molding tires as claimed in claim 1,wherein means are provided for rotating said template relative to saidmold.
 4. Apparatus for molding tires as claimed in claim 1, whereinmeans are provided for supporting said template member which permitssaid template member to be rotated about its generally radical directionlength axis when desired.
 5. Apparatus for molding tires including incombination a mold having an inner surface which defines the outer shapeof a tire, means mounting said mold for rotation about its axis, meansfor rotating said mold about its axis, wall means defining an opening tothe interior of said mold for introducing flowable and hardenableelastomeric material thereinto, at least one template member positionedwithin said mold and extending therein in a generally radial direction,said template member comprising a plate member having an outerperimetric surface which conforms to the inner cross sectional shape ofthe tire to be molded and having a relatively small thickness dimensionin the circumferential direction of the mold, the shape of the tirebeing determined by the space between said perimetric surface of saidtemplate member and said inner surface of said mold.
 6. Apparatus formolding tires as claimed in claim 5, wherein means are provided forfixedly locating said template member within said mold during rotationof the same.
 7. Apparatus for molding tires as claimed in claim 5,wherein means are provided for rotating said template member relative tosaid mold.
 8. Apparatus for molding tires as claimed in claim 5, whereinmeans are provided for supporting said template member which permitssaid template member to be rotated about its generally radial directionlength axis when desired.
 9. Apparatus for molding tires as claimed inclaim 5, wherein said mold has a circumferentially extending openingthereinto having a width dimension in the axial direction of said mold,the thickness dimension of said plate member being less than said widthdimension of said circumferentially extending opening.
 10. Apparatus formolding tires as claimed in claim 1, wherein said mold has acircumferentially extending opening thereinto having a width dimensionin the axial direction of said mold, the thickness dimension of saidplate member being less than said width dimension of saidcircumferentially extending opening.